Fluid device



Feb. 16, 1965 1-. D. READER 3,169,550

FLUID DEVICE Filed June 6, 1962 FIG], 1

INVENTOR 45 TREVOR DRAKE READER E Y W W A T TORNE Y 3,169,550 FLUID DEVICE Trevor Drake Reader, Wayne, Pa., assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed June 6, 1962, Ser. No. 200,527 7 Claims. (Cl. 137-62525) This invention relates to control devices, and more particularly to a high speed valve for selectively controlling the pressure in a line from a negative to a positive value and vice versa.

The prior art teaches a great many valves operating on different principles, such as mechanical, electromechanical or pneumatic principles. A common disadvantage of these prior art devices is that they operate too slowly for certain special applications. For example, in electronic computers a serious problem is the operating speed of the non-electronic equipment since this speed greatly influences the overall operating speed of the computer.

Tape handling machines forming part of a computer, for example, must be equipped to provide starting and stopping operations of the tape at high frequencies. In many machines, engagement and disengagement of the tape with its drive capstan is achieved by pneumatically controlling the friction between the tape and the capstan. Engagement of the tape is obtained by creating a vacuum between the tape and the periphery of the capstan. The tape is disengaged from the capstan by providing a thin layer of air at slight over pressure between the tape and the periphery of the capstan.

It is accordingly an object of the invention to provide a valving device capable of high operating frequencies.

It is a further object of the invention to provide a valve which enables the selective provision of a positive or a negative pressure in a line at high switching speeds and frequencies.

Further objects and advantages will be more readily understood from the following description and the accompanying drawing in which:

FIG. 1 illustrates a cross-section of a valve according to the invention. 7

FIG. 2 illustrates an operative stage of the embodiment of FIG. 1. r

FIG. 3 illustrates a part of a modification of the valve of FIG. 1.

Referring now to the drawing, the embodiment of the invention illustrated by FIG. 1 discloses a magnetic field, indicated as 10, of substantially toroidal form. The magnetic field is generated by a cylindrical permanent magnet 12. The magnet 12 is located at the bottom of a cylin a conical portion 22. The cylindrical portion 20 and the conical portion 22 are connected to the permanent mag- United States Patent net 12. All sited parts which make up the magnetic circuit, with the exception of gap 18, are made of suitable magnetically permeable material.

It willbe understood that the joining surfaces of the parts which constitute the magnetic circuit of the magnetic to disc 26. The helix 28 is thus suspended approximately intermediate gap 18 and is substantially concentric with the longitudinal axis of the permanent magnet 12. Consequently, the planes of the coils of the helix 28 are substan- I 3,1695% Patented Feb. 16, 1965 tially parallel to the lines of force of the magnetic field 10 traversing the gap 18.

The helix 28 is made of electrically conductive material.

Both ends of the helix are adapted to be connected to electrical terminals (not illustrated) so that'an electric potential may be applied between the ends of the helix to produce current therethrough. A ring 30 of flexible material extends from the outer periphery of cylindrical portion 29 to the intermediate coil 32 of helix 28. The connection of the ring 30 with the periphery of cylindrical portion 20 and that with the coil 32 is such as to be airtight. The ring 30 is flexible to the extent that it does not constrain the axial movements in either direction of coil 32. The flexible ring 30 divides the interior space of the helix 28 into two sections 34 and 36. For reasons apparent from the description which follows, the section 34 will be called hereinafter the vacuum section 34 of helix 28. The section 36 will be called the pressure section 36 of helix 28.

The cylindrical portion 20 is provided with a duct 38 and a duct 40. One end of duct 38 opens into the vacuum a section 34 of helix 28. To the other end of duct 38 tubing means 44 are connected. The tubing means 44 are disposed to connect vacuum section 34 via duct 38 to a source of negative pressure, such as a vacuum pump. One end of duct 40 opens into the pressure section 36 of helix 28.

To the other end of duct 40, tubing means 42 are connected. The tubing means 42 are disposed to connect the pressure section 36 via duct 40 with a source of positive pressure, such as an air compressor.

In the ring 16 there is provided an outlet duct 46. One

' end of outlet duct 46 opens into the gap 18'. The other end of the duct is provided with outlet tubing means 48. The tubing means 48 are disposed to connect the gap 18 crosses in FIG. 2, in accordance with the custom in electrodynamics. With the direction of the magnetic field 10 asillustrated in FIG. 1,I the resulting electrodynamic forces will result in all coils being moved toward the left. The result is that all coils of helix 28 within the vacuum section 34 are compressed axially and all coils within the pressure section 36 are removed further from each other, increasing their mutual spacing. The compressed coils of vacuum outlet duct 46. Therefore, the full positive pressure presection 34 cause this section to become sealed off from the vailing in the pressure section 36 will be transmitted to helix will be moved toward the right so that the mutual spacing of the coils of the vacuum section 34 will be increased and the coils of the pressure section 36 will be compressed. The compression of the coils in the pressure section 36 will result in this section becoming sealed from A helical, resilient member or helix 28 is connected with its one extremity to disc 24 with its other extremity the outlet duct 46. The increased separation of the coils in the vacuum section 34 will result in a communication between the vacuum section 34'and the outlet duct 46 so that a negative pressure in the latter will prevail.

It will be appreciated that the device according to the invention provides for a .valve with a very high valving frequency. As described above, and as shown in the drawing, a very rapid and effective change from a condi tion of negative pressure to a condition of positive presdrical cross-section it will be understood that coils with another cross-section may be used. Coils with a rectangular cross-section, for example, may provide a more eflicient seal between two adjacent coils.

It will also be understood that it may prove desirable to provide the coils of helix 28 with a layer of a suitable insulating material so as to provide a proper electrical insulation between them. Such insulating material may be made of resilient material thereby contributing to an even better sealing between adjacent coils.

Referring now more particularly to FIG. 3, there is shown a part of a modification of the device according to FIG. 1. Like parts are indicated by like numerals. A comparison of both figures discloses that the main difference between the two devices is that in FIG. 3 the helix 28 is divided electrically into two equal halves by providing for a ground or reference connection at the winding 32. By means of associated switching apparatus, the current through the coils of the vacuum section 34 can be controlled independently of the current through the coils of the pressure section 36. The switching apparatus, in itself of conventional construction, may comprise the switches S and S Both switches S and S are interconnected by known means, such as a relay, so that if one switch is closed the other is open. Switch 5, controls the flow of current from a battery 47 through the coils of the vacuum section 34, switch S the current from the battery 47 through the coils of the pressure section 36. If switch S is closed, as depicted in FIG. 3, the current will flow through the coils of the vacuum section. As explained above, this causes the coils in the vacuum section to become compressed resulting in a sealing off of the vacuum section from the outlet 46. During this compressing action of the coils in the vacuum section, the coils of the pressure section do not carry current since switch S is open. The latter coils are therefore not moved by electrodynamic forces. The coils act thereby to dampen the movement of the coils of the vacuum section. It will be appreciated that by such damping action the phenomenon of bounce in the coils of the vacuum section is greatly reduced. The phenomenon of bounce in this respect may be expressed as the tendency of the coils to separate upon first impact due to the high energy of their motion as a result of the sudden current pulse.

While there have been shown and described the fundamental novel features of the invention as applied to a preferred embodiment, modifications within the scope of the invention will be apparent to those skilled in the art. For example, the source of the magnetic field need not be a permanent magnet, but an electromagnet may be used to generate the required field. Besides, the exciting force for oscillating the helix need not be of electrodynamic nature. For instance mechanical, acoustical or electromagnetic excitation could be used. Further, the invention is not confined to one fluid only, but fluids of different kinds may be used. Neither is the invention confined to a fluid of gaseous nature, but liquids may be considered as well.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

I claim:

1. A high speed bistable device for controlling the flow of a fluid therethrough, comprising a first inlet, a second inlet and an outlet, said first inlet being connected to a source of sub-atmospheric pressure, said second inlet being connected to a source of over-atmospheric pressure, a helical member of resilient material having its adjacent coils in close axial proximity so as to define a space between such coils, means to support said helical member in the path of flow of said fluid between said first and said second inlet and said outlet, partitioning means intermediate said helical member separating said first inlet from said second inlet, means to provide an electromagnet field said helical member in one direction resulting in a unidirectional axial motion of said coils, means to reverse said current through said helical member to compress said helical member in a second direction resulting in a uni-directional axial motion of said turns in said other direction.

2. A high speed bistable device for controlling the flow of a fluid therethrough comprising a vacuum tight hollow enclosure defined by a cylindrical body and a toroidal body and two end walls, said cylindrical body and said toroidal body being made of magnetizable material, said end Walls supporting said toroidal body in concentric spaced relationship with said cylindrical body, a helical member of resilient material having its adjacent coils in close axial proximity so as to define a space between such coils, means to suspend said helical member between said end walls intermediate said enclosure and concentric with said cylindrical body, partitioning means intermediate said helical member defining a separated first and second section within said helical member, a first duct within said toroidal body, a second and a third duct within said cylindrical body, one end of said first duct opening into said enclosure, one end of said second duct opening into said first section, one end of said third duct opening into said second section, means to connect the other end of said second duct with a source of sub-atmospheric pressure, means to connect the other end of said third duct with a source of over-atomospheric pressure, means to induce a magnetic field in said enclosure parallel to the windings of said helical member, and means to drive an electric current through said helical member to compress said helical member in either direction.

3. A device to selectively control a positive and a negative pressure in an outlet port comprising a cylindrical can of magnetizable material having a bottom and a longitudinal axis, a cylindrical permanent magnet within said can, said magnet being connected at one of its poles to said bottom and extending therefrom in con centric spaced relationship with said can, a cylindrical extension of magnetizable material connected to the other pole of said magnet, a toroidal ring of magnetizable material extending along the inner periphery of said can,

' a first partition and a second partition arranged in parallel spaced relationship on said extension, said first and said second partition defining together with said extension and said toroidal ring a hollow toroidal enclosure, a helix of resilient material having its adjacent coils in close axial proximity so as to define a space between such coils, said helix being suspended between said first and said second partition intermediate said enclosure and concentric with said extension, a flexible partition having an outer periphery extending from said cylindrical extension to said helix, said flexible partition being attached at its outer periphery to the intermediate coil of said helix, said flexible partition defining a first and a second section within said helix, a first duct within said toroidal ring, a second and a third duct within said cylindrical extension, one end of said first duct ending into said enclosure, one end of said second duct opening into said first section, one end of said third duct opening into said second section, tubing means to connect the other end of said first duct with a source of sub-atmospheric pressure, tubing means to connect the other end of said third duct with a source of over-atmospheric pressure, and means to drive an electric current through said helix to compress said helix in either direction.

4. A device for controlling the flow of fluid therethrough comprising an inlet and an outlet, conduit means connecting said inlet to said outlet, a coil element disposed within said conduit means, and means for applying an electrical current through said coil element to compress said coil element to block the passage of said fluid from said inlet to said outlet.

5. A device for controlling the flow of fluid therethrough comprising a pair of inlets, an outlet, conduit all means connecting said pair of inlets to said outlet, a coil element disposed within said conduit means, and means for applying an electrical current through said coil element to compress said coil element to block the passage of said fluid from said one of said inlets to said outlet and to permit the passage of said fluid from the other of said inlets to said outlet.

6. A device for controlling the flow of fluid therethrough comprising a pair of inlets, an outlet, conduit means connecting said pair of inlets to said outlet, a coil element disposed within said conduit means, and means for applying an electrical current through said coil element to compress a portion of said coil element to block the passage of said fluid from one of said inlets to said outlets and to expand another portion of said coil to 15 permit the passage of said fluid from the other of said vintlets to said outlet.

7. The invention as set forth in claim 6 wherein the center of said coil element is connected to the means for 5 applying an'electn'cal current.

Reterences (Jilted in the file of this patent UNITED STATES PATENTS 2,088,174 Paullin July 27, 1937 2,102,400 Wunsche Dec. 14, 1937 2,363,279 Anschicks Nov. 21, 1944 3,082,925 MacNeill et a1. Mar. 26, 1963 FOREIGN PATENTS 1,116,952 Germany Nov. 9, 1961 

4. A DEVICE FOR CONTROLLNG THE FLOW OF FLUID THERETHROUGH COMPRISING AN INLET AND AN OUTLET, CONDUIT MEANS CONNECTING SAID INLET TO SAID OUTLET, A COIL ELEMENT DISPOSED WITHIN SAID CONDUIT MEANS, AND MEANS FOR APPLYING AN ELECTRICAL CURRENT THROUGH SAID COIL ELEMENT TO COMPRESS SAID COIL ELEMENT TO BLOCK THE PASSAGE OF SAID FLUID FROM SAID INLET TO SAID OUTLET. 